Anyone have a main character but a different protagonist in their story?

Same as title. I have a main character who the story follows and the chapter POVs is mostly through their perspective. I also have a protagonist who the story centers around and majority of the plot and main events is influenced by that said protagonist. Anyone have a similar thing going on? How do you manage the story so that one doesn't overshadow the other? Or do you let that happen, and why?